- Linux-kselftest-mirror - lists.linaro.org

[RFC PATCH v2 0/3] Add testable code specifications

by Gabriele Paoloni

[1] was an initial proposal defining testable code specifications for some functions in /drivers/char/mem.c. However a Guideline to write such specifications was missing and test cases tracing to such specifications were missing. This patchset represents a next step and is organised as follows: - patch 1/3 contains the Guideline for writing code specifications - patch 2/3 contains examples of code specfications defined for some functions of drivers/char/mem.c - patch 3/3 contains examples of selftests that map to some code specifications of patch 2/3 [1] https://lore.kernel.org/all/20250821170419.70668-1-gpaoloni@redhat.com/ --- Changes from v1: 1) Added a Guideline to write code specifications in the Linux Kernel Documentation 2) Addressed Greg KH comments in /drivers/char/mem.c 3) Added example of test cases mapping to the code specifications in /drivers/char/mem.c --- Alessandro Carminati (1): selftests/devmem: initial testset Gabriele Paoloni (2): Documentation: add guidelines for writing testable code specifications /dev/mem: Add initial documentation of memory_open() and mem_fops .../doc-guide/code-specifications.rst | 208 +++++++ Documentation/doc-guide/index.rst | 1 + drivers/char/mem.c | 231 ++++++- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/devmem/Makefile | 13 + tools/testing/selftests/devmem/debug.c | 25 + tools/testing/selftests/devmem/debug.h | 14 + tools/testing/selftests/devmem/devmem.c | 200 ++++++ tools/testing/selftests/devmem/ram_map.c | 250 ++++++++ tools/testing/selftests/devmem/ram_map.h | 38 ++ tools/testing/selftests/devmem/secret.c | 46 ++ tools/testing/selftests/devmem/secret.h | 13 + tools/testing/selftests/devmem/tests.c | 569 ++++++++++++++++++ tools/testing/selftests/devmem/tests.h | 45 ++ tools/testing/selftests/devmem/utils.c | 379 ++++++++++++ tools/testing/selftests/devmem/utils.h | 119 ++++ 16 files changed, 2146 insertions(+), 6 deletions(-) create mode 100644 Documentation/doc-guide/code-specifications.rst create mode 100644 tools/testing/selftests/devmem/Makefile create mode 100644 tools/testing/selftests/devmem/debug.c create mode 100644 tools/testing/selftests/devmem/debug.h create mode 100644 tools/testing/selftests/devmem/devmem.c create mode 100644 tools/testing/selftests/devmem/ram_map.c create mode 100644 tools/testing/selftests/devmem/ram_map.h create mode 100644 tools/testing/selftests/devmem/secret.c create mode 100644 tools/testing/selftests/devmem/secret.h create mode 100644 tools/testing/selftests/devmem/tests.c create mode 100644 tools/testing/selftests/devmem/tests.h create mode 100644 tools/testing/selftests/devmem/utils.c create mode 100644 tools/testing/selftests/devmem/utils.h -- 2.48.1

2 weeks, 2 days

7
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[PATCH v11 0/9] support FEAT_LSUI

by Yeoreum Yun

Since Armv9.6, FEAT_LSUI supplies the load/store instructions for previleged level to access to access user memory without clearing PSTATE.PAN bit. This patchset support FEAT_LSUI and applies in futex atomic operation and user_swpX emulation where can replace from ldxr/st{l}xr pair implmentation with clearing PSTATE.PAN bit to correspondant load/store unprevileged atomic operation without clearing PSTATE.PAN bit. Patch Sequences ================ Patch #1 adds cpufeature for FEAT_LSUI Patch #2-#3 expose FEAT_LSUI to guest Patch #4 adds Kconfig for FEAT_LSUI Patch #5-#6 support futex atomic-op with FEAT_LSUI Patch #7-#9 support user_swpX emulation with FEAT_LSUI Patch History ============== from v10 to v11: - use cast instruction to emulate deprecated swpb instruction - https://lore.kernel.org/all/20251103163224.818353-1-yeoreum.yun@arm.com/ from v9 to v10: - apply FEAT_LSUI to user_swpX emulation. - add test coverage for LSUI bit in ID_AA64ISAR3_EL1 - rebase to v6.18-rc4 - https://lore.kernel.org/all/20250922102244.2068414-1-yeoreum.yun@arm.com/ from v8 to v9: - refotoring __lsui_cmpxchg64() - rebase to v6.17-rc7 - https://lore.kernel.org/all/20250917110838.917281-1-yeoreum.yun@arm.com/ from v7 to v8: - implements futex_atomic_eor() and futex_atomic_cmpxchg() with casalt with C helper. - Drop the small optimisation on ll/sc futex_atomic_set operation. - modify some commit message. - https://lore.kernel.org/all/20250816151929.197589-1-yeoreum.yun@arm.com/ from v6 to v7: - wrap FEAT_LSUI with CONFIG_AS_HAS_LSUI in cpufeature - remove unnecessary addition of indentation. - remove unnecessary mte_tco_enable()/disable() on LSUI operation. - https://lore.kernel.org/all/20250811163635.1562145-1-yeoreum.yun@arm.com/ from v5 to v6: - rebase to v6.17-rc1 - https://lore.kernel.org/all/20250722121956.1509403-1-yeoreum.yun@arm.com/ from v4 to v5: - remove futex_ll_sc.h futext_lsui and lsui.h and move them to futex.h - reorganize the patches. - https://lore.kernel.org/all/20250721083618.2743569-1-yeoreum.yun@arm.com/ from v3 to v4: - rebase to v6.16-rc7 - modify some patch's title. - https://lore.kernel.org/all/20250617183635.1266015-1-yeoreum.yun@arm.com/ from v2 to v3: - expose FEAT_LUSI to guest - add help section for LUSI Kconfig - https://lore.kernel.org/all/20250611151154.46362-1-yeoreum.yun@arm.com/ from v1 to v2: - remove empty v9.6 menu entry - locate HAS_LUSI in cpucaps in order - https://lore.kernel.org/all/20250611104916.10636-1-yeoreum.yun@arm.com/ Yeoreum Yun (9): arm64: cpufeature: add FEAT_LSUI KVM: arm64: expose FEAT_LSUI to guest KVM: arm64: kselftest: set_id_regs: add test for FEAT_LSUI arm64: Kconfig: Detect toolchain support for LSUI arm64: futex: refactor futex atomic operation arm64: futex: support futex with FEAT_LSUI arm64: separate common LSUI definitions into lsui.h arm64: armv8_deprecated: convert user_swpX to inline function arm64: armv8_deprecated: apply FEAT_LSUI for swpX emulation. arch/arm64/Kconfig | 5 + arch/arm64/include/asm/futex.h | 291 +++++++++++++++--- arch/arm64/include/asm/lsui.h | 25 ++ arch/arm64/kernel/armv8_deprecated.c | 111 +++++-- arch/arm64/kernel/cpufeature.c | 10 + arch/arm64/kvm/sys_regs.c | 3 +- arch/arm64/tools/cpucaps | 1 + .../testing/selftests/kvm/arm64/set_id_regs.c | 1 + 8 files changed, 381 insertions(+), 66 deletions(-) create mode 100644 arch/arm64/include/asm/lsui.h base-commit: 6146a0f1dfae5d37442a9ddcba012add260bceb0 -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

2 weeks, 2 days

2
13
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[PATCH net-next v8 00/14] vsock: add namespace support to vhost-vsock

by Bobby Eshleman

This series adds namespace support to vhost-vsock and loopback. It does not add namespaces to any of the other guest transports (virtio-vsock, hyperv, or vmci). The current revision supports two modes: local and global. Local mode is complete isolation of namespaces, while global mode is complete sharing between namespaces of CIDs (the original behavior). The mode is set using /proc/sys/net/vsock/ns_mode. Modes are per-netns and write-once. This allows a system to configure namespaces independently (some may share CIDs, others are completely isolated). This also supports future possible mixed use cases, where there may be namespaces in global mode spinning up VMs while there are mixed mode namespaces that provide services to the VMs, but are not allowed to allocate from the global CID pool (this mode not implemented in this series). If a socket or VM is created when a namespace is global but the namespace changes to local, the socket or VM will continue working normally. That is, the socket or VM assumes the mode behavior of the namespace at the time the socket/VM was created. The original mode is captured in vsock_create() and so occurs at the time of socket(2) and accept(2) for sockets and open(2) on /dev/vhost-vsock for VMs. This prevents a socket/VM connection from suddenly breaking due to a namespace mode change. Any new sockets/VMs created after the mode change will adopt the new mode's behavior. Additionally, added tests for the new namespace features: tools/testing/selftests/vsock/vmtest.sh 1..30 ok 1 vm_server_host_client ok 2 vm_client_host_server ok 3 vm_loopback ok 4 ns_host_vsock_ns_mode_ok ok 5 ns_host_vsock_ns_mode_write_once_ok ok 6 ns_global_same_cid_fails ok 7 ns_local_same_cid_ok ok 8 ns_global_local_same_cid_ok ok 9 ns_local_global_same_cid_ok ok 10 ns_diff_global_host_connect_to_global_vm_ok ok 11 ns_diff_global_host_connect_to_local_vm_fails ok 12 ns_diff_global_vm_connect_to_global_host_ok ok 13 ns_diff_global_vm_connect_to_local_host_fails ok 14 ns_diff_local_host_connect_to_local_vm_fails ok 15 ns_diff_local_vm_connect_to_local_host_fails ok 16 ns_diff_global_to_local_loopback_local_fails ok 17 ns_diff_local_to_global_loopback_fails ok 18 ns_diff_local_to_local_loopback_fails ok 19 ns_diff_global_to_global_loopback_ok ok 20 ns_same_local_loopback_ok ok 21 ns_same_local_host_connect_to_local_vm_ok ok 22 ns_same_local_vm_connect_to_local_host_ok ok 23 ns_mode_change_connection_continue_vm_ok ok 24 ns_mode_change_connection_continue_host_ok ok 25 ns_mode_change_connection_continue_both_ok ok 26 ns_delete_vm_ok ok 27 ns_delete_host_ok ok 28 ns_delete_both_ok ok 29 ns_loopback_global_global_late_module_load_ok ok 30 ns_loopback_local_local_late_module_load_fails SUMMARY: PASS=30 SKIP=0 FAIL=0 Dependent on series: https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements… Thanks again for everyone's help and reviews! Signed-off-by: Bobby Eshleman <bobbyeshleman(a)gmail.com> To: Stefano Garzarella <sgarzare(a)redhat.com> To: Shuah Khan <shuah(a)kernel.org> To: David S. Miller <davem(a)davemloft.net> To: Eric Dumazet <edumazet(a)google.com> To: Jakub Kicinski <kuba(a)kernel.org> To: Paolo Abeni <pabeni(a)redhat.com> To: Simon Horman <horms(a)kernel.org> To: Stefan Hajnoczi <stefanha(a)redhat.com> To: Michael S. Tsirkin <mst(a)redhat.com> To: Jason Wang <jasowang(a)redhat.com> To: Xuan Zhuo <xuanzhuo(a)linux.alibaba.com> To: Eugenio Pérez <eperezma(a)redhat.com> To: K. Y. Srinivasan <kys(a)microsoft.com> To: Haiyang Zhang <haiyangz(a)microsoft.com> To: Wei Liu <wei.liu(a)kernel.org> To: Dexuan Cui <decui(a)microsoft.com> To: Bryan Tan <bryan-bt.tan(a)broadcom.com> To: Vishnu Dasa <vishnu.dasa(a)broadcom.com> To: Broadcom internal kernel review list <bcm-kernel-feedback-list(a)broadcom.com> Cc: virtualization(a)lists.linux.dev Cc: netdev(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org Cc: kvm(a)vger.kernel.org Cc: linux-hyperv(a)vger.kernel.org Cc: berrange(a)redhat.com Changes in v8: - Break generic cleanup/refactoring patches into standalone series, remove those from this series - Link to dependency: https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements… - Link to v7: https://lore.kernel.org/r/20251021-vsock-vmtest-v7-0-0661b7b6f081@meta.com Changes in v7: - fix hv_sock build - break out vmtest patches into distinct, more well-scoped patches - change `orig_net_mode` to `net_mode` - many fixes and style changes in per-patch change sets (see individual patches for specific changes) - optimize `virtio_vsock_skb_cb` layout - update commit messages with more useful descriptions - vsock_loopback: use orig_net_mode instead of current net mode - add tests for edge cases (ns deletion, mode changing, loopback module load ordering) - Link to v6: https://lore.kernel.org/r/20250916-vsock-vmtest-v6-0-064d2eb0c89d@meta.com Changes in v6: - define behavior when mode changes to local while socket/VM is alive - af_vsock: clarify description of CID behavior - af_vsock: use stronger langauge around CID rules (dont use "may") - af_vsock: improve naming of buf/buffer - af_vsock: improve string length checking on proc writes - vsock_loopback: add space in struct to clarify lock protection - vsock_loopback: do proper cleanup/unregister on vsock_loopback_exit() - vsock_loopback: use virtio_vsock_skb_net() instead of sock_net() - vsock_loopback: set loopback to NULL after kfree() - vsock_loopback: use pernet_operations and remove callback mechanism - vsock_loopback: add macros for "global" and "local" - vsock_loopback: fix length checking - vmtest.sh: check for namespace support in vmtest.sh - Link to v5: https://lore.kernel.org/r/20250827-vsock-vmtest-v5-0-0ba580bede5b@meta.com Changes in v5: - /proc/net/vsock_ns_mode -> /proc/sys/net/vsock/ns_mode - vsock_global_net -> vsock_global_dummy_net - fix netns lookup in vhost_vsock to respect pid namespaces - add callbacks for vsock_loopback to avoid circular dependency - vmtest.sh loads vsock_loopback module - remove vsock_net_mode_can_set() - change vsock_net_write_mode() to return true/false based on success - make vsock_net_mode enum instead of u8 - Link to v4: https://lore.kernel.org/r/20250805-vsock-vmtest-v4-0-059ec51ab111@meta.com Changes in v4: - removed RFC tag - implemented loopback support - renamed new tests to better reflect behavior - completed suite of tests with permutations of ns modes and vsock_test as guest/host - simplified socat bridging with unix socket instead of tcp + veth - only use vsock_test for success case, socat for failure case (context in commit message) - lots of cleanup Changes in v3: - add notion of "modes" - add procfs /proc/net/vsock_ns_mode - local and global modes only - no /dev/vhost-vsock-netns - vmtest.sh already merged, so new patch just adds new tests for NS - Link to v2: https://lore.kernel.org/kvm/20250312-vsock-netns-v2-0-84bffa1aa97a@gmail.com Changes in v2: - only support vhost-vsock namespaces - all g2h namespaces retain old behavior, only common API changes impacted by vhost-vsock changes - add /dev/vhost-vsock-netns for "opt-in" - leave /dev/vhost-vsock to old behavior - removed netns module param - Link to v1: https://lore.kernel.org/r/20200116172428.311437-1-sgarzare@redhat.com Changes in v1: - added 'netns' module param to vsock.ko to enable the network namespace support (disabled by default) - added 'vsock_net_eq()' to check the "net" assigned to a socket only when 'netns' support is enabled - Link to RFC: https://patchwork.ozlabs.org/cover/1202235/ --- Bobby Eshleman (14): vsock: a per-net vsock NS mode state vsock/virtio: pack struct virtio_vsock_skb_cb vsock: add netns to vsock skb cb vsock: add netns to vsock core vsock/loopback: add netns support vsock/virtio: add netns to virtio transport common vhost/vsock: add netns support selftests/vsock: add namespace helpers to vmtest.sh selftests/vsock: prepare vm management helpers for namespaces selftests/vsock: add tests for proc sys vsock ns_mode selftests/vsock: add namespace tests for CID collisions selftests/vsock: add tests for host <-> vm connectivity with namespaces selftests/vsock: add tests for namespace deletion and mode changes selftests/vsock: add tests for module loading order MAINTAINERS | 1 + drivers/vhost/vsock.c | 48 +- include/linux/virtio_vsock.h | 47 +- include/net/af_vsock.h | 70 ++- include/net/net_namespace.h | 4 + include/net/netns/vsock.h | 22 + net/vmw_vsock/af_vsock.c | 264 +++++++- net/vmw_vsock/virtio_transport.c | 7 +- net/vmw_vsock/virtio_transport_common.c | 21 +- net/vmw_vsock/vsock_loopback.c | 89 ++- tools/testing/selftests/vsock/vmtest.sh | 1044 ++++++++++++++++++++++++++++++- 11 files changed, 1532 insertions(+), 85 deletions(-) --- base-commit: 962ac5ca99a5c3e7469215bf47572440402dfd59 change-id: 20250325-vsock-vmtest-b3a21d2102c2 prerequisite-message-id: <20251022-vsock-selftests-fixes-and-improvements-v1-0-edeb179d6463(a)meta.com> prerequisite-patch-id: a2eecc3851f2509ed40009a7cab6990c6d7cfff5 prerequisite-patch-id: 501db2100636b9c8fcb3b64b8b1df797ccbede85 prerequisite-patch-id: ba1a2f07398a035bc48ef72edda41888614be449 prerequisite-patch-id: fd5cc5445aca9355ce678e6d2bfa89fab8a57e61 prerequisite-patch-id: 795ab4432ffb0843e22b580374782e7e0d99b909 prerequisite-patch-id: 1499d263dc933e75366c09e045d2125ca39f7ddd prerequisite-patch-id: f92d99bb1d35d99b063f818a19dcda999152d74c prerequisite-patch-id: e3296f38cdba6d903e061cff2bbb3e7615e8e671 prerequisite-patch-id: bc4662b4710d302d4893f58708820fc2a0624325 prerequisite-patch-id: f8991f2e98c2661a706183fde6b35e2b8d9aedcf prerequisite-patch-id: 44bf9ed69353586d284e5ee63d6fffa30439a698 prerequisite-patch-id: d50621bc630eeaf608bbaf260370c8dabf6326df Best regards, -- Bobby Eshleman <bobbyeshleman(a)meta.com>

2 weeks, 2 days

2
35
0 0

[PATCH v5 0/7] platform/chrome: Fix a possible UAF via revocable

by Tzung-Bi Shih

This is a follow-up series of [1]. It tries to fix a possible UAF in the fops of cros_ec_chardev after the underlying protocol device has gone by using revocable. The 1st patch introduces the revocable which is an implementation of ideas from the talk [2]. The 2nd and 3rd patches add test cases for revocable in Kunit and selftest. The 4th patch converts existing protocol devices to resource providers of cros_ec_device. The 5th - 7th are PoC patches for showing the use case of "Replace file operations" below. --- I came out with 2 possible usages of revocable. 1. Use primitive APIs Use the primitive APIs of revocable directly. The file operations make sure the resources are available when using them. This is what the series original proposed[3][4]. Even though it has the finest grain for accessing the resources, it makes the user code verbose. Per feedback from the community, I'm looking for some subsystem level helpers so that user code can be simlper. 2. Replace file operations Replace filp->f_op to revocable-aware warppers. The warppers make sure the resources are available in the file operations. The user code needs to provide a callback .try_access() to tell the wrappers where/how to *save* the pointers of resources. Known drawback: - The warppers reserve the resources for all file operations even if they might be unused. - The user code still needs to be revocable-aware. - The whole file operation becomes a SRCU read-side critical section. Are there any functions can't be called in the critical section? If there is, the file operations may not be awared of that. See 5th - 7th patches for an example usage. [1] https://lore.kernel.org/chrome-platform/20250721044456.2736300-6-tzungbi@ke… [2] https://lpc.events/event/17/contributions/1627/ [3] https://lore.kernel.org/chrome-platform/20250912081718.3827390-5-tzungbi@ke… [4] https://lore.kernel.org/chrome-platform/20250912081718.3827390-6-tzungbi@ke… v5: - Rebase onto next-20251015. - Add more context about the PoC. - Support multiple revocable providers in the PoC. v4: https://lore.kernel.org/chrome-platform/20250923075302.591026-1-tzungbi@ker… - Rebase onto next-20250922. - Remove the 5th patch from v3. - Add fops replacement PoC in 5th - 7th patches. v3: https://lore.kernel.org/chrome-platform/20250912081718.3827390-1-tzungbi@ke… - Rebase onto https://lore.kernel.org/chrome-platform/20250828083601.856083-1-tzungbi@ker… and next-20250912. - The 4th patch changed accordingly. v2: https://lore.kernel.org/chrome-platform/20250820081645.847919-1-tzungbi@ker… - Rename "ref_proxy" -> "revocable". - Add test cases in Kunit and selftest. v1: https://lore.kernel.org/chrome-platform/20250814091020.1302888-1-tzungbi@ke… Tzung-Bi Shih (7): revocable: Revocable resource management revocable: Add Kunit test cases selftests: revocable: Add kselftest cases platform/chrome: Protect cros_ec_device lifecycle with revocable revocable: Add fops replacement char: misc: Leverage revocable fops replacement platform/chrome: cros_ec_chardev: Secure cros_ec_device via revocable .../driver-api/driver-model/index.rst | 1 + .../driver-api/driver-model/revocable.rst | 87 +++++++ MAINTAINERS | 9 + drivers/base/Kconfig | 8 + drivers/base/Makefile | 5 +- drivers/base/revocable.c | 233 ++++++++++++++++++ drivers/base/revocable_test.c | 110 +++++++++ drivers/char/misc.c | 8 + drivers/platform/chrome/cros_ec.c | 5 + drivers/platform/chrome/cros_ec_chardev.c | 22 +- fs/Makefile | 2 +- fs/fs_revocable.c | 154 ++++++++++++ include/linux/fs.h | 2 + include/linux/fs_revocable.h | 21 ++ include/linux/miscdevice.h | 4 + include/linux/platform_data/cros_ec_proto.h | 4 + include/linux/revocable.h | 53 ++++ tools/testing/selftests/Makefile | 1 + .../selftests/drivers/base/revocable/Makefile | 7 + .../drivers/base/revocable/revocable_test.c | 116 +++++++++ .../drivers/base/revocable/test-revocable.sh | 39 +++ .../base/revocable/test_modules/Makefile | 10 + .../revocable/test_modules/revocable_test.c | 188 ++++++++++++++ 23 files changed, 1086 insertions(+), 3 deletions(-) create mode 100644 Documentation/driver-api/driver-model/revocable.rst create mode 100644 drivers/base/revocable.c create mode 100644 drivers/base/revocable_test.c create mode 100644 fs/fs_revocable.c create mode 100644 include/linux/fs_revocable.h create mode 100644 include/linux/revocable.h create mode 100644 tools/testing/selftests/drivers/base/revocable/Makefile create mode 100644 tools/testing/selftests/drivers/base/revocable/revocable_test.c create mode 100755 tools/testing/selftests/drivers/base/revocable/test-revocable.sh create mode 100644 tools/testing/selftests/drivers/base/revocable/test_modules/Makefile create mode 100644 tools/testing/selftests/drivers/base/revocable/test_modules/revocable_test.c -- 2.51.0.788.g6d19910ace-goog

2 weeks, 2 days

5
34
0 0

[PATCH v2 0/5] introduce VM_MAYBE_GUARD and make it sticky

by Lorenzo Stoakes

Currently, guard regions are not visible to users except through /proc/$pid/pagemap, with no explicit visibility at the VMA level. This makes the feature less useful, as it isn't entirely apparent which VMAs may have these entries present, especially when performing actions which walk through memory regions such as those performed by CRIU. This series addresses this issue by introducing the VM_MAYBE_GUARD flag which fulfils this role, updating the smaps logic to display an entry for these. The semantics of this flag are that a guard region MAY be present if set (we cannot be sure, as we can't efficiently track whether an MADV_GUARD_REMOVE finally removes all the guard regions in a VMA) - but if not set the VMA definitely does NOT have any guard regions present. It's problematic to establish this flag without further action, because that means that VMAs with guard regions in them become non-mergeable with adjacent VMAs for no especially good reason. To work around this, this series also introduces the concept of 'sticky' VMA flags - that is flags which: a. if set in one VMA and not in another still permit those VMAs to be merged (if otherwise compatible). b. When they are merged, the resultant VMA must have the flag set. The VMA logic is updated to propagate these flags correctly. Additionally, VM_MAYBE_GUARD being an explicit VMA flag allows us to solve an issue with file-backed guard regions - previously these established an anon_vma object for file-backed mappings solely to have vma_needs_copy() correctly propagate guard region mappings to child processes. We introduce a new flag alias VM_COPY_ON_FORK (which currently only specifies VM_MAYBE_GUARD) and update vma_needs_copy() to check explicitly for this flag and to copy page tables if it is present, which resolves this issue. Additionally, we add the ability for allow-listed VMA flags to be atomically writable with only mmap/VMA read locks held. The only flag we allow so far is VM_MAYBE_GUARD, which we carefully ensure does not cause any races by being allowed to do so. This allows us to maintain guard region installation as a read-locked operation and not endure the overhead of obtaining a write lock here. Finally we introduce extensive VMA userland tests to assert that the sticky VMA logic behaves correctly as well as guard region self tests to assert that smaps visibility is correctly implemented. v2: * Separated out userland VMA tests for sticky behaviour as per Suren. * Added the concept of atomic writable VMA flags as per Pedro and Vlastimil. * Made VM_MAYBE_GUARD an atomic writable flag so we don't have to take a VMA write lock in madvise() as per Pedro and Vlastimil. v1: https://lore.kernel.org/all/cover.1761756437.git.lorenzo.stoakes@oracle.com/ Lorenzo Stoakes (5): mm: introduce VM_MAYBE_GUARD and make visible in /proc/$pid/smaps mm: add atomic VMA flags, use VM_MAYBE_GUARD as such mm: implement sticky, copy on fork VMA flags tools/testing/vma: add VMA sticky userland tests selftests/mm/guard-regions: add smaps visibility test Documentation/filesystems/proc.rst | 1 + fs/proc/task_mmu.c | 1 + include/linux/mm.h | 58 ++++++++++ include/trace/events/mmflags.h | 1 + mm/madvise.c | 22 ++-- mm/memory.c | 3 + mm/vma.c | 22 ++-- tools/testing/selftests/mm/guard-regions.c | 120 +++++++++++++++++++++ tools/testing/selftests/mm/vm_util.c | 5 + tools/testing/selftests/mm/vm_util.h | 1 + tools/testing/vma/vma.c | 89 +++++++++++++-- tools/testing/vma/vma_internal.h | 35 ++++++ 12 files changed, 330 insertions(+), 28 deletions(-) -- 2.51.0

2 weeks, 2 days

4
22
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[RFC 0/2] xdp: Delegate fast path return decision to page_pool

by Dragos Tatulea

This small series proposes the removal of the BPF_RI_F_RF_NO_DIRECT XDP flag in favour of page_pool's internal page_pool_napi_local() check which can override a non-direct recycle into a direct one if the right conditions are met., This was discussed on the mailing list on several occasions [1][2]. The first patch adds additional benchmarking code to the page_pool benchmark. The second patch has the actual change with a proper explanation and measurements. It remains to be debated if the whole BPF_RI_F_RF_NO_DIRECT mechanism should be deleted or only its use in xdp_return_frame_rx_napi(). There is still the unresolved issue of drivers that don't support page_pool NAPI recycling. This series could be extended to add that support. Otherwise those drivers would end up with slow path recycling for XDP. [1] https://lore.kernel.org/all/8d165026-1477-46cb-94d4-a01e1da40833@kernel.org/ [2] https://lore.kernel.org/all/20250918084823.372000-1-dtatulea@nvidia.com/ Dragos Tatulea (2): page_pool: add benchmarking for napi-based recycling xdp: Delegate fast path return decision to page_pool drivers/net/veth.c | 2 - include/linux/filter.h | 22 ----- include/net/xdp.h | 2 +- kernel/bpf/cpumap.c | 2 - net/bpf/test_run.c | 2 - net/core/filter.c | 2 +- net/core/xdp.c | 24 ++--- .../bench/page_pool/bench_page_pool_simple.c | 92 ++++++++++++++++++- 8 files changed, 104 insertions(+), 44 deletions(-) -- 2.50.1

2 weeks, 2 days

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[PATCH v8 28/28] tracing: selftests: Add pKVM trace remote tests

by Vincent Donnefort

Run the trace remote selftests with the pKVM trace remote "hypervisor". Cc: Shuah Khan <skhan(a)linuxfoundation.org> Cc: linux-kselftest(a)vger.kernel.org Signed-off-by: Vincent Donnefort <vdonnefort(a)google.com> diff --git a/tools/testing/selftests/ftrace/test.d/remotes/pkvm/buffer_size.tc b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/buffer_size.tc new file mode 100644 index 000000000000..2de07e4d72fe --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/buffer_size.tc @@ -0,0 +1,11 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test pkvm hypervisor trace buffer size +# requires: remotes/hypervisor/write_event + +SOURCE_REMOTE_TEST=1 +. $TEST_DIR/remotes/buffer_size.tc + +set -e +setup_remote "hypervisor" +test_buffer_size diff --git a/tools/testing/selftests/ftrace/test.d/remotes/pkvm/reset.tc b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/reset.tc new file mode 100644 index 000000000000..48afc51627e8 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/reset.tc @@ -0,0 +1,11 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test pkvm hypervisor trace buffer reset +# requires: remotes/hypervisor/write_event + +SOURCE_REMOTE_TEST=1 +. $TEST_DIR/remotes/reset.tc + +set -e +setup_remote "hypervisor" +test_reset diff --git a/tools/testing/selftests/ftrace/test.d/remotes/pkvm/trace.tc b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/trace.tc index 49dca7c3861a..00aed1c2e650 100644 --- a/tools/testing/selftests/ftrace/test.d/remotes/pkvm/trace.tc +++ b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/trace.tc @@ -1,9 +1,10 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 -# description: Test pkvm hypervisor tracing pipe +# description: Test pkvm hypervisor non-consuming trace read +# requires: remotes/hypervisor/write_event SOURCE_REMOTE_TEST=1 -. $TEST_DIR/remotes/trace_pipe.tc +. $TEST_DIR/remotes/trace.tc set -e setup_remote "hypervisor" diff --git a/tools/testing/selftests/ftrace/test.d/remotes/pkvm/trace_pipe.tc b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/trace_pipe.tc new file mode 100644 index 000000000000..b63339aca380 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/trace_pipe.tc @@ -0,0 +1,11 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test pkvm hypervisor consuming trace read +# requires: remotes/hypervisor/write_event + +SOURCE_REMOTE_TEST=1 +. $TEST_DIR/remotes/trace_pipe.tc + +set -e +setup_remote "hypervisor" +test_trace_pipe diff --git a/tools/testing/selftests/ftrace/test.d/remotes/pkvm/unloading.tc b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/unloading.tc new file mode 100644 index 000000000000..eb1640a927cc --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/pkvm/unloading.tc @@ -0,0 +1,11 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test pkvm hypervisor trace buffer unloading +# requires: remotes/hypervisor/write_event + +SOURCE_REMOTE_TEST=1 +. $TEST_DIR/remotes/unloading.tc + +set -e +setup_remote "hypervisor" +test_unloading -- 2.51.2.1041.gc1ab5b90ca-goog

2 weeks, 2 days

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[PATCH v8 15/28] tracing: selftests: Add trace remote tests

by Vincent Donnefort

Exercise the tracefs interface for trace remote with a set of tests to check: * loading/unloading (unloading.tc) * reset (reset.tc) * size changes (buffer_size.tc) * consuming read (trace_pipe.tc) * non-consuming read (trace.tc) Cc: Shuah Khan <skhan(a)linuxfoundation.org> Cc: linux-kselftest(a)vger.kernel.org Signed-off-by: Vincent Donnefort <vdonnefort(a)google.com> diff --git a/tools/testing/selftests/ftrace/test.d/remotes/buffer_size.tc b/tools/testing/selftests/ftrace/test.d/remotes/buffer_size.tc new file mode 100644 index 000000000000..1a43280ffa97 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/buffer_size.tc @@ -0,0 +1,25 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test trace remote buffer size +# requires: remotes/test + +. $TEST_DIR/remotes/functions + +test_buffer_size() +{ + echo 0 > tracing_on + assert_unloaded + + echo 4096 > buffer_size_kb + echo 1 > tracing_on + assert_loaded + + echo 0 > tracing_on + echo 7 > buffer_size_kb +} + +if [ -z "$SOURCE_REMOTE_TEST" ]; then + set -e + setup_remote_test + test_buffer_size +fi diff --git a/tools/testing/selftests/ftrace/test.d/remotes/functions b/tools/testing/selftests/ftrace/test.d/remotes/functions new file mode 100644 index 000000000000..97a09d564a34 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/functions @@ -0,0 +1,88 @@ +# SPDX-License-Identifier: GPL-2.0 + +setup_remote() +{ + local name=$1 + + [ -e $TRACING_DIR/remotes/$name/write_event ] || exit_unresolved + + cd remotes/$name/ + echo 0 > tracing_on + clear_trace + echo 7 > buffer_size_kb + echo 0 > events/enable + echo 1 > events/$name/selftest/enable + echo 1 > tracing_on +} + +setup_remote_test() +{ + [ -d $TRACING_DIR/remotes/test/ ] || modprobe remote_test || exit_unresolved + + setup_remote "test" +} + +assert_loaded() +{ + grep -q "(loaded)" buffer_size_kb +} + +assert_unloaded() +{ + grep -q "(unloaded)" buffer_size_kb +} + +dump_trace_pipe() +{ + output=$(mktemp $TMPDIR/remote_test.XXXXXX) + cat trace_pipe > $output & + pid=$! + sleep 1 + kill -1 $pid + + echo $output +} + +check_trace() +{ + start_id="$1" + end_id="$2" + file="$3" + + # Ensure the file is not empty + test -n "$(head $file)" + + prev_ts=0 + id=0 + + # Only keep <timestamp> <id> + tmp=$(mktemp $TMPDIR/remote_test.XXXXXX) + sed -e 's/\[[0-9]*\]\s*$[0-9]*.[0-9]*$: [a-z]* id=$[0-9]*$/\1 \2/' $file > $tmp + + while IFS= read -r line; do + ts=$(echo $line | cut -d ' ' -f 1) + id=$(echo $line | cut -d ' ' -f 2) + + test $(echo "$ts>$prev_ts" | bc) -eq 1 + test $id -eq $start_id + + prev_ts=$ts + start_id=$((start_id + 1)) + done < $tmp + + test $id -eq $end_id + rm $tmp +} + +get_cpu_ids() +{ + sed -n 's/^processor\s*:\s*$[0-9]\+$.*/\1/p' /proc/cpuinfo +} + +get_page_size() { + sed -ne 's/^.*data.*size:$[0-9][0-9]*$.*/\1/p' events/header_page +} + +get_selftest_event_size() { + sed -ne 's/^.*field:.*;.*size:$[0-9][0-9]*$;.*/\1/p' events/*/selftest/format | awk '{s+=$1} END {print s}' +} diff --git a/tools/testing/selftests/ftrace/test.d/remotes/reset.tc b/tools/testing/selftests/ftrace/test.d/remotes/reset.tc new file mode 100644 index 000000000000..4d176349b2bc --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/reset.tc @@ -0,0 +1,90 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test trace remote reset +# requires: remotes/test + +. $TEST_DIR/remotes/functions + +check_reset() +{ + write_event_path="write_event" + taskset="" + + clear_trace + + # Is the buffer empty? + output=$(dump_trace_pipe) + test $(wc -l $output | cut -d ' ' -f1) -eq 0 + + if $(echo $(pwd) | grep -q "per_cpu/cpu"); then + write_event_path="../../write_event" + cpu_id=$(echo $(pwd) | sed -e 's/.*per_cpu\/cpu//') + taskset="taskset -c $cpu_id" + fi + rm $output + + # Can we properly write a new event? + $taskset echo 7890 > $write_event_path + output=$(dump_trace_pipe) + test $(wc -l $output | cut -d ' ' -f1) -eq 1 + grep -q "id=7890" $output + rm $output +} + +test_global_interface() +{ + output=$(mktemp $TMPDIR/remote_test.XXXXXX) + + # Confidence check + echo 123456 > write_event + output=$(dump_trace_pipe) + grep -q "id=123456" $output + rm $output + + # Reset single event + echo 1 > write_event + check_reset + + # Reset lost events + for i in $(seq 1 10000); do + echo 1 > write_event + done + check_reset +} + +test_percpu_interface() +{ + [ "$(get_cpu_ids | wc -l)" -ge 2 ] || return 0 + + for cpu in $(get_cpu_ids); do + taskset -c $cpu echo 1 > write_event + done + + check_non_empty=0 + for cpu in $(get_cpu_ids); do + cd per_cpu/cpu$cpu/ + + if [ $check_non_empty -eq 0 ]; then + check_reset + check_non_empty=1 + else + # Check we have only reset 1 CPU + output=$(dump_trace_pipe) + test $(wc -l $output | cut -d ' ' -f1) -eq 1 + rm $output + fi + cd - + done +} + +test_reset() +{ + test_global_interface + test_percpu_interface +} + +if [ -z "$SOURCE_REMOTE_TEST" ]; then + set -e + setup_remote_test + test_reset +fi diff --git a/tools/testing/selftests/ftrace/test.d/remotes/trace.tc b/tools/testing/selftests/ftrace/test.d/remotes/trace.tc new file mode 100644 index 000000000000..081133ec45ff --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/trace.tc @@ -0,0 +1,127 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test trace remote non-consuming read +# requires: remotes/test + +. $TEST_DIR/remotes/functions + +test_trace() +{ + echo 0 > tracing_on + assert_unloaded + + echo 7 > buffer_size_kb + echo 1 > tracing_on + assert_loaded + + # Simple test: Emit few events and try to read them + for i in $(seq 1 8); do + echo $i > write_event + done + + check_trace 1 8 trace + + # + # Test interaction with consuming read + # + + cat trace_pipe > /dev/null & + pid=$! + + sleep 1 + kill $pid + + test $(wc -l < trace) -eq 0 + + for i in $(seq 16 32); do + echo $i > write_event + done + + check_trace 16 32 trace + + # + # Test interaction with reset + # + + echo 0 > trace + + test $(wc -l < trace) -eq 0 + + for i in $(seq 1 8); do + echo $i > write_event + done + + check_trace 1 8 trace + + # + # Test interaction with lost events + # + + # Ensure the writer is not on the reader page by reloading the buffer + echo 0 > tracing_on + echo 0 > trace + assert_unloaded + echo 1 > tracing_on + assert_loaded + + # Ensure ring-buffer overflow by emitting events from the same CPU + for cpu in $(get_cpu_ids); do + break + done + + events_per_page=$(($(get_page_size) / $(get_selftest_event_size))) # Approx: does not take TS into account + nr_events=$(($events_per_page * 2)) + for i in $(seq 1 $nr_events); do + taskset -c $cpu echo $i > write_event + done + + id=$(sed -n -e '1s/\[[0-9]*\]\s*[0-9]*.[0-9]*: [a-z]* id=$[0-9]*$/\1/p' trace) + test $id -ne 1 + + check_trace $id $nr_events trace + + # + # Test per-CPU interface + # + echo 0 > trace + + for cpu in $(get_cpu_ids) ; do + taskset -c $cpu echo $cpu > write_event + done + + for cpu in $(get_cpu_ids); do + cd per_cpu/cpu$cpu/ + + check_trace $cpu $cpu trace + + cd - > /dev/null + done + + # + # Test with hotplug + # + + [ "$(get_cpu_ids | wc -l)" -ge 2 ] || return 0 + + echo 0 > trace + + for cpu in $(get_cpu_ids); do + echo 0 > /sys/devices/system/cpu/cpu$cpu/online + break + done + + for i in $(seq 1 8); do + echo $i > write_event + done + + check_trace 1 8 trace + + echo 1 > /sys/devices/system/cpu/cpu$cpu/online +} + +if [ -z "$SOURCE_REMOTE_TEST" ]; then + set -e + + setup_remote_test + test_trace +fi diff --git a/tools/testing/selftests/ftrace/test.d/remotes/trace_pipe.tc b/tools/testing/selftests/ftrace/test.d/remotes/trace_pipe.tc new file mode 100644 index 000000000000..d28eaee10c7c --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/trace_pipe.tc @@ -0,0 +1,127 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test trace remote consuming read +# requires: remotes/test + +. $TEST_DIR/remotes/functions + +test_trace_pipe() +{ + echo 0 > tracing_on + assert_unloaded + + # Emit events from the same CPU + for cpu in $(get_cpu_ids); do + break + done + + # + # Simple test: Emit enough events to fill few pages + # + + echo 1024 > buffer_size_kb + echo 1 > tracing_on + assert_loaded + + events_per_page=$(($(get_page_size) / $(get_selftest_event_size))) + nr_events=$(($events_per_page * 4)) + + output=$(mktemp $TMPDIR/remote_test.XXXXXX) + + cat trace_pipe > $output & + pid=$! + + for i in $(seq 1 $nr_events); do + taskset -c $cpu echo $i > write_event + done + + echo 0 > tracing_on + sleep 1 + kill $pid + + check_trace 1 $nr_events $output + + rm $output + + # + # Test interaction with lost events + # + + assert_unloaded + echo 7 > buffer_size_kb + echo 1 > tracing_on + assert_loaded + + nr_events=$((events_per_page * 2)) + for i in $(seq 1 $nr_events); do + taskset -c $cpu echo $i > write_event + done + + output=$(dump_trace_pipe) + + lost_events=$(sed -n -e '1s/CPU:.*\[LOST $[0-9]*$ EVENTS\]/\1/p' $output) + test -n "$lost_events" + + id=$(sed -n -e '2s/\[[0-9]*\]\s*[0-9]*.[0-9]*: [a-z]* id=$[0-9]*$/\1/p' $output) + test "$id" -eq $(($lost_events + 1)) + + # Drop [LOST EVENTS] line + sed -i '1d' $output + + check_trace $id $nr_events $output + + rm $output + + # + # Test per-CPU interface + # + + echo 0 > trace + echo 1 > tracing_on + + for cpu in $(get_cpu_ids); do + taskset -c $cpu echo $cpu > write_event + done + + for cpu in $(get_cpu_ids); do + cd per_cpu/cpu$cpu/ + output=$(dump_trace_pipe) + + check_trace $cpu $cpu $output + + rm $output + cd - > /dev/null + done + + # + # Test interaction with hotplug + # + + [ "$(get_cpu_ids | wc -l)" -ge 2 ] || return 0 + + echo 0 > trace + + for cpu in $(get_cpu_ids); do + echo 0 > /sys/devices/system/cpu/cpu$cpu/online + break + done + + for i in $(seq 1 8); do + echo $i > write_event + done + + output=$(dump_trace_pipe) + + check_trace 1 8 $output + + rm $output + + echo 1 > /sys/devices/system/cpu/cpu$cpu/online +} + +if [ -z "$SOURCE_REMOTE_TEST" ]; then + set -e + + setup_remote_test + test_trace_pipe +fi diff --git a/tools/testing/selftests/ftrace/test.d/remotes/unloading.tc b/tools/testing/selftests/ftrace/test.d/remotes/unloading.tc new file mode 100644 index 000000000000..cac2190183f6 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/remotes/unloading.tc @@ -0,0 +1,41 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test trace remote unloading +# requires: remotes/test + +. $TEST_DIR/remotes/functions + +test_unloading() +{ + # No reader, writing + assert_loaded + + # No reader, no writing + echo 0 > tracing_on + assert_unloaded + + # 1 reader, no writing + cat trace_pipe & + pid=$! + sleep 1 + assert_loaded + kill $pid + assert_unloaded + + # No reader, no writing, events + echo 1 > tracing_on + echo 1 > write_event + echo 0 > tracing_on + assert_loaded + + # Test reset + clear_trace + assert_unloaded +} + +if [ -z "$SOURCE_REMOTE_TEST" ]; then + set -e + + setup_remote_test + test_unloading +fi -- 2.51.2.1041.gc1ab5b90ca-goog

2 weeks, 2 days

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[PATCH v6 0/2] platform/chrome: Fix an UAF via revocable primitive APIs

by Tzung-Bi Shih

The series is separated from [1] to show the independency and compare potential use cases easier. This use case uses the primitive revocable APIs directly. It relies on the revocable core part [2]. It tries to fix an UAF in the fops of cros_ec_chardev after the underlying protocol device has gone by using revocable. The file operations make sure the resources are available when using them. Even though it has the finest grain for accessing the resources, it makes the user code verbose. Per feedback from the community, I'm looking for some subsystem level helpers so that user code can be simlper. The 1st patch converts existing protocol devices to resource providers of cros_ec_device. The 2nd patch converts cros_ec_chardev to a resource consumer of cros_ec_device to fix the UAF. [1] https://lore.kernel.org/chrome-platform/20251016054204.1523139-1-tzungbi@ke… [2] https://lore.kernel.org/chrome-platform/20251106152330.11733-1-tzungbi@kern… v6: - New, separated from an existing series. Tzung-Bi Shih (2): platform/chrome: Protect cros_ec_device lifecycle with revocable platform/chrome: cros_ec_chardev: Consume cros_ec_device via revocable drivers/platform/chrome/cros_ec.c | 5 ++ drivers/platform/chrome/cros_ec_chardev.c | 71 ++++++++++++++++----- include/linux/platform_data/cros_ec_proto.h | 4 ++ 3 files changed, 65 insertions(+), 15 deletions(-) -- 2.48.1

2 weeks, 2 days

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[PATCH v8 00/15] Consolidate iommu page table implementations (AMD)

by Jason Gunthorpe

[Joerg, can you put this and vtd in linux-next please. The vtd series is still good at v3 thanks] Currently each of the iommu page table formats duplicates all of the logic to maintain the page table and perform map/unmap/etc operations. There are several different versions of the algorithms between all the different formats. The io-pgtable system provides an interface to help isolate the page table code from the iommu driver, but doesn't provide tools to implement the common algorithms. This makes it very hard to improve the state of the pagetable code under the iommu domains as any proposed improvement needs to alter a large number of different driver code paths. Combined with a lack of software based testing this makes improvement in this area very hard. iommufd wants several new page table operations: - More efficient map/unmap operations, using iommufd's batching logic - unmap that returns the physical addresses into a batch as it progresses - cut that allows splitting areas so large pages can have holes poked in them dynamically (ie guestmemfd hitless shared/private transitions) - More agressive freeing of table memory to avoid waste - Fragmenting large pages so that dirty tracking can be more granular - Reassembling large pages so that VMs can run at full IO performance in migration/dirty tracking error flows - KHO integration for kernel live upgrade Together these are algorithmically complex enough to be a very significant task to go and implement in all the page table formats we support. Just the "server" focused drivers use almost all the formats (ARMv8 S1&S2 / x86 PAE / AMDv1 / VT-d SS / RISCV) Instead of doing the duplicated work, this series takes the first step to consolidate the algorithms into one places. In spirit it is similar to the work Christoph did a few years back to pull the redundant get_user_pages() implementations out of the arch code into core MM. This unlocked a great deal of improvement in that space in the following years. I would like to see the same benefit in iommu as well. My first RFC showed a bigger picture with all most all formats and more algorithms. This series reorganizes that to be narrowly focused on just enough to convert the AMD driver to use the new mechanism. kunit tests are provided that allow good testing of the algorithms and all formats on x86, nothing is arch specific. AMD is one of the simpler options as the HW is quite uniform with few different options/bugs while still requiring the complicated contiguous pages support. The HW also has a very simple range based invalidation approach that is easy to implement. The AMD v1 and AMD v2 page table formats are implemented bit for bit identical to the current code, tested using a compare kunit test that checks against the io-pgtable version (on github, see below). Updating the AMD driver to replace the io-pgtable layer with the new stuff is fairly straightforward now. The layering is fixed up in the new version so that all the invalidation goes through function pointers. Several small fixing patches have come out of this as I've been fixing the problems that the test suite uncovers in the current code, and implementing the fixed version in iommupt. On performance, there is a quite wide variety of implementation designs across all the drivers. Looking at some key performance across the main formats: iommu_map(): pgsz ,avg new,old ns, min new,old ns , min % (+ve is better) 2^12, 53,66 , 51,63 , 19.19 (AMDV1) 256*2^12, 386,1909 , 367,1795 , 79.79 256*2^21, 362,1633 , 355,1556 , 77.77 2^12, 56,62 , 52,59 , 11.11 (AMDv2) 256*2^12, 405,1355 , 357,1292 , 72.72 256*2^21, 393,1160 , 358,1114 , 67.67 2^12, 55,65 , 53,62 , 14.14 (VT-d second stage) 256*2^12, 391,518 , 332,512 , 35.35 256*2^21, 383,635 , 336,624 , 46.46 2^12, 57,65 , 55,63 , 12.12 (ARM 64 bit) 256*2^12, 380,389 , 361,369 , 2.02 256*2^21, 358,419 , 345,400 , 13.13 iommu_unmap(): pgsz ,avg new,old ns, min new,old ns , min % (+ve is better) 2^12, 69,88 , 65,85 , 23.23 (AMDv1) 256*2^12, 353,6498 , 331,6029 , 94.94 256*2^21, 373,6014 , 360,5706 , 93.93 2^12, 71,72 , 66,69 , 4.04 (AMDv2) 256*2^12, 228,891 , 206,871 , 76.76 256*2^21, 254,721 , 245,711 , 65.65 2^12, 69,87 , 65,82 , 20.20 (VT-d second stage) 256*2^12, 210,321 , 200,315 , 36.36 256*2^21, 255,349 , 238,342 , 30.30 2^12, 72,77 , 68,74 , 8.08 (ARM 64 bit) 256*2^12, 521,357 , 447,346 , -29.29 256*2^21, 489,358 , 433,345 , -25.25 * Above numbers include additional patches to remove the iommu_pgsize() overheads. gcc 13.3.0, i7-12700 This version provides fairly consistent performance across formats. ARM unmap performance is quite different because this version supports contiguous pages and uses a very different algorithm for unmapping. Though why it is so worse compared to AMDv1 I haven't figured out yet. The per-format commits include a more detailed chart. There is a second branch: https://github.com/jgunthorpe/linux/commits/iommu_pt_all Containing supporting work and future steps: - ARM short descriptor (32 bit), ARM long descriptor (64 bit) formats - RISCV format and RISCV conversion https://github.com/jgunthorpe/linux/commits/iommu_pt_riscv - Support for a DMA incoherent HW page table walker - VT-d second stage format and VT-d conversion https://github.com/jgunthorpe/linux/commits/iommu_pt_vtd - DART v1 & v2 format - Draft of a iommufd 'cut' operation to break down huge pages - A compare test that checks the iommupt formats against the iopgtable interface, including updating AMD to have a working iopgtable and patches to make VT-d have an iopgtable for testing. - A performance test to micro-benchmark map and unmap against iogptable My strategy is to go one by one for the drivers: - AMD driver conversion - RISCV page table and driver - Intel VT-d driver and VTDSS page table - Flushing improvements for RISCV - ARM SMMUv3 And concurrently work on the algorithm side: - debugfs content dump, like VT-d has - Cut support - Increase/Decrease page size support - map/unmap batching - KHO As we make more algorithm improvements the value to convert the drivers increases. This is on github: https://github.com/jgunthorpe/linux/commits/iommu_pt v8: - Remove unused to_amdv1pt/common_to_amdv1pt/to_x86_64_pt/common_to_x86_64_pt - Fix 32 bit udiv compile failure in the kunit v7: https://patch.msgid.link/r/0-v7-ab019a8791e2+175b8-iommu_pt_jgg@nvidia.com - Rebase to v6.18-rc2 - Improve comments and documentation - Add a few missed __sme_sets() for AMD CC - Rename pt_iommu_flush_ops -> pt_iommu_driver_ops VT-D -> VT-d pt_clear_entry -> pt_clear_entries pt_entry_write_is_dirty -> pt_entry_is_write_dirty pt_entry_set_write_clean -> pt_entry_make_write_clean - Tidy some of the map flow into a new function do_map() - Fix ffz64() v6: https://patch.msgid.link/r/0-v6-0fb54a1d9850+36b-iommu_pt_jgg@nvidia.com - Improve comments and documentation - Rename pt_entry_oa_full -> pt_entry_oa_exact pt_has_system_page -> pt_has_system_page_size pt_max_output_address_lg2 -> pt_max_oa_lg2 log2_f*() -> vaf* / oaf* / f*_t pt_item_fully_covered -> pt_entry_fully_covered - Fix missed constant propogation causing division - Consolidate debugging checks to pt_check_install_leaf_args() - Change collect->ignore_mapped to check_mapped - Shuffle some hunks around to more appropriate patches - Two new mini kunit tests v5: https://patch.msgid.link/r/0-v5-116c4948af3d+68091-iommu_pt_jgg@nvidia.com - Text grammar updates and kdoc fixes v4: https://patch.msgid.link/r/0-v4-0d6a6726a372+18959-iommu_pt_jgg@nvidia.com - Rebase on v6.16-rc3 - Integrate the HATS/HATDis changes - Remove 'default n' from kconfig - Remove unused 'PT_FIXED_TOP_LEVEL' - Improve comments and documentation - Fix some compile warnings from kbuild robots v3: https://patch.msgid.link/r/0-v3-a93aab628dbc+521-iommu_pt_jgg@nvidia.com - Rebase on v6.16-rc2 - s/PT_ENTRY_WORD_SIZE/PT_ITEM_WORD_SIZE/s to follow the language better - Comment and documentation updates - Add PT_TOP_PHYS_MASK to help manage alignment restrictions on the top pointer - Add missed force_aperture = true - Make pt_iommu_deinit() take care of the not-yet-inited error case internally as AMD/RISCV/VTD all shared this logic - Change gather_range() into gather_range_pages() so it also deals with the page list. This makes the following cache flushing series simpler - Fix missed update of unmap->unmapped in some error cases - Change clear_contig() to order the gather more logically - Remove goto from the error handling in __map_range_leaf() - s/log2_/oalog2_/ in places where the argument is an oaddr_t - Pass the pts to pt_table_install64/32() - Do not use SIGN_EXTEND for the AMDv2 page table because of Vasant's information on how PASID 0 works. v2: https://patch.msgid.link/r/0-v2-5c26bde5c22d+58b-iommu_pt_jgg@nvidia.com - AMD driver only, many code changes RFC: https://lore.kernel.org/all/0-v1-01fa10580981+1d-iommu_pt_jgg@nvidia.com/ Cc: Michael Roth <michael.roth(a)amd.com> Cc: Alexey Kardashevskiy <aik(a)amd.com> Cc: Pasha Tatashin <pasha.tatashin(a)soleen.com> Cc: James Gowans <jgowans(a)amazon.com> Signed-off-by: Jason Gunthorpe <jgg(a)nvidia.com> Alejandro Jimenez (1): iommu/amd: Use the generic iommu page table Jason Gunthorpe (14): genpt: Generic Page Table base API genpt: Add Documentation/ files iommupt: Add the basic structure of the iommu implementation iommupt: Add the AMD IOMMU v1 page table format iommupt: Add iova_to_phys op iommupt: Add unmap_pages op iommupt: Add map_pages op iommupt: Add read_and_clear_dirty op iommupt: Add a kunit test for Generic Page Table iommupt: Add a mock pagetable format for iommufd selftest to use iommufd: Change the selftest to use iommupt instead of xarray iommupt: Add the x86 64 bit page table format iommu/amd: Remove AMD io_pgtable support iommupt: Add a kunit test for the IOMMU implementation .clang-format | 1 + Documentation/driver-api/generic_pt.rst | 142 ++ Documentation/driver-api/index.rst | 1 + drivers/iommu/Kconfig | 2 + drivers/iommu/Makefile | 1 + drivers/iommu/amd/Kconfig | 5 +- drivers/iommu/amd/Makefile | 2 +- drivers/iommu/amd/amd_iommu.h | 1 - drivers/iommu/amd/amd_iommu_types.h | 110 +- drivers/iommu/amd/io_pgtable.c | 577 -------- drivers/iommu/amd/io_pgtable_v2.c | 370 ------ drivers/iommu/amd/iommu.c | 538 ++++---- drivers/iommu/generic_pt/.kunitconfig | 13 + drivers/iommu/generic_pt/Kconfig | 68 + drivers/iommu/generic_pt/fmt/Makefile | 26 + drivers/iommu/generic_pt/fmt/amdv1.h | 411 ++++++ drivers/iommu/generic_pt/fmt/defs_amdv1.h | 21 + drivers/iommu/generic_pt/fmt/defs_x86_64.h | 21 + drivers/iommu/generic_pt/fmt/iommu_amdv1.c | 15 + drivers/iommu/generic_pt/fmt/iommu_mock.c | 10 + drivers/iommu/generic_pt/fmt/iommu_template.h | 48 + drivers/iommu/generic_pt/fmt/iommu_x86_64.c | 11 + drivers/iommu/generic_pt/fmt/x86_64.h | 255 ++++ drivers/iommu/generic_pt/iommu_pt.h | 1162 +++++++++++++++++ drivers/iommu/generic_pt/kunit_generic_pt.h | 713 ++++++++++ drivers/iommu/generic_pt/kunit_iommu.h | 183 +++ drivers/iommu/generic_pt/kunit_iommu_pt.h | 487 +++++++ drivers/iommu/generic_pt/pt_common.h | 358 +++++ drivers/iommu/generic_pt/pt_defs.h | 329 +++++ drivers/iommu/generic_pt/pt_fmt_defaults.h | 233 ++++ drivers/iommu/generic_pt/pt_iter.h | 636 +++++++++ drivers/iommu/generic_pt/pt_log2.h | 122 ++ drivers/iommu/io-pgtable.c | 4 - drivers/iommu/iommufd/Kconfig | 1 + drivers/iommu/iommufd/iommufd_test.h | 11 +- drivers/iommu/iommufd/selftest.c | 438 +++---- include/linux/generic_pt/common.h | 167 +++ include/linux/generic_pt/iommu.h | 271 ++++ include/linux/io-pgtable.h | 2 - include/linux/irqchip/riscv-imsic.h | 3 +- tools/testing/selftests/iommu/iommufd.c | 60 +- tools/testing/selftests/iommu/iommufd_utils.h | 12 + 42 files changed, 6229 insertions(+), 1612 deletions(-) create mode 100644 Documentation/driver-api/generic_pt.rst delete mode 100644 drivers/iommu/amd/io_pgtable.c delete mode 100644 drivers/iommu/amd/io_pgtable_v2.c create mode 100644 drivers/iommu/generic_pt/.kunitconfig create mode 100644 drivers/iommu/generic_pt/Kconfig create mode 100644 drivers/iommu/generic_pt/fmt/Makefile create mode 100644 drivers/iommu/generic_pt/fmt/amdv1.h create mode 100644 drivers/iommu/generic_pt/fmt/defs_amdv1.h create mode 100644 drivers/iommu/generic_pt/fmt/defs_x86_64.h create mode 100644 drivers/iommu/generic_pt/fmt/iommu_amdv1.c create mode 100644 drivers/iommu/generic_pt/fmt/iommu_mock.c create mode 100644 drivers/iommu/generic_pt/fmt/iommu_template.h create mode 100644 drivers/iommu/generic_pt/fmt/iommu_x86_64.c create mode 100644 drivers/iommu/generic_pt/fmt/x86_64.h create mode 100644 drivers/iommu/generic_pt/iommu_pt.h create mode 100644 drivers/iommu/generic_pt/kunit_generic_pt.h create mode 100644 drivers/iommu/generic_pt/kunit_iommu.h create mode 100644 drivers/iommu/generic_pt/kunit_iommu_pt.h create mode 100644 drivers/iommu/generic_pt/pt_common.h create mode 100644 drivers/iommu/generic_pt/pt_defs.h create mode 100644 drivers/iommu/generic_pt/pt_fmt_defaults.h create mode 100644 drivers/iommu/generic_pt/pt_iter.h create mode 100644 drivers/iommu/generic_pt/pt_log2.h create mode 100644 include/linux/generic_pt/common.h create mode 100644 include/linux/generic_pt/iommu.h base-commit: 8440410283bb5533b676574211f31f030a18011b -- 2.43.0

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